#!/bin/bash
#
# Developed by Fred Weinhaus 6/10/2017 .......... revised 6/10/2017
#
# ------------------------------------------------------------------------------
# 
# Licensing:
# 
# Copyright © Fred Weinhaus
# 
# My scripts are available free of charge for non-commercial use, ONLY.
# 
# For use of my scripts in commercial (for-profit) environments or 
# non-free applications, please contact me (Fred Weinhaus) for 
# licensing arrangements. My email address is fmw at alink dot net.
# 
# If you: 1) redistribute, 2) incorporate any of these scripts into other 
# free applications or 3) reprogram them in another scripting language, 
# then you must contact me for permission, especially if the result might 
# be used in a commercial or for-profit environment.
# 
# My scripts are also subject, in a subordinate manner, to the ImageMagick 
# license, which can be found at: http://www.imagemagick.org/script/license.php
# 
# ------------------------------------------------------------------------------
# 
####
#
# USAGE: sketchetch [-m mode] [-e etch] [-B brightness] [-S saturation] [-h hue] 
# [-c color] [-C coloramt] [-t type] [infile] [outfile]
# 
# USAGE: sketchetch [-help]
# 
# OPTIONS:
# 
# -m     mode           mode for processing; choices are: normal, grayscale, 
#                       colorized, shaded and composite; default=normal
# -e     etch           etch amount; integer>0; default=4
# -B     brightness     brightness percent change; -100<=integer<=100; default=0
# -S     saturation     saturation percent change; -100<=integer<=100; default=0
# -H     hue            hue angle change in degrees; -360<=integer<=360; default=0
# -c     color          colorizing color; any valid opaque IM color is allowed; 
#                       default=sienna1
# -C     coloramt       colorizing amount; 0<=integer<=100; default=50
# -t     type           type of composite (compose mode); choices are: hardlight, 
#                       overlay, and softlight; default=hardlight
#
###
# 
# NAME: SKETCHETCH 
# 
# PURPOSE: To create an etch-like sketch from an image.
# 
# DESCRIPTION: PIP creates an etch-like sketch from an image. There is an option for 
# modes of normal, grayscale, colorized grayscale, shaded grayscale and three different 
# composite types.
# 
# 
# ARGUMENTS: 
# 
# -m mode ... MODE for processing. The choices are: normal, grayscale, colorized 
# (from grayscale), shaded (from grayscale) and composite. The default=normal.
# 
# -e etch ... ETCH amount. Values are integers>0. The default=4.
# 
# -B brightness ... BRIGHTNESS percent change of the image. Value are -100<=integer<=100. 
# The default=0.
# 
# -S saturation ... SATURATION percent change of the image. Value are -100<=integer<=100. 
# The default=0.
# 
# -H hue ... HUE angle change of the image in degrees. Value are -360<=integer<=360. 
# The default=0.
# 
# -c color ... COLOR is the colorizing color. Any valid opaque IM color is allowed. 
# The default=sienna1.
# 
# -C coloramt ... COLORAMT is the colorizing amount. Values are 0<=integers<=100. 
# The default=50.
# 
# -t type ... TYPE of composite (compose mode). The choices are: hardlight, overlay 
# and softlight. The default=hardlight
# 
# Reference: 
# http://www.creativecloseup.com/color-ink-sketch-effect-in-photoshop
# 
# CAVEAT: No guarantee that this script will work on all platforms, 
# nor that trapping of inconsistent parameters is complete and 
# foolproof. Use At Your Own Risk. 
# 
######
# 
# set default values
mode="normal"		# normal, grayscale, colorized (grayscale), shaded (grayscale), composite
etch=4				# etch amount
brightness=0		# brightness change in percent
saturation=0		# saturation change in percent
hue=0				# hue change in deg
color="sienna1"		# colorizing color
coloramt=0			# color amount
type="hardlight"	# compose type; hardlight, overlay, softlight

# set directory for temporary files
dir="."    # suggestions are dir="." or dir="/tmp"

# set up functions to report Usage and Usage with Description
PROGNAME=`type $0 | awk '{print $3}'`  # search for executable on path
PROGDIR=`dirname $PROGNAME`            # extract directory of program
PROGNAME=`basename $PROGNAME`          # base name of program
usage1() 
	{
	echo >&2 ""
	echo >&2 "$PROGNAME:" "$@"
	sed >&2 -e '1,/^####/d;  /^###/g;  /^#/!q;  s/^#//;  s/^ //;  4,$p' "$PROGDIR/$PROGNAME"
	}
usage2() 
	{
	echo >&2 ""
	echo >&2 "$PROGNAME:" "$@"
	sed >&2 -e '1,/^####/d;  /^######/g;  /^#/!q;  s/^#*//;  s/^ //;  4,$p' "$PROGDIR/$PROGNAME"
	}


# function to report error messages
errMsg()
	{
	echo ""
	echo $1
	echo ""
	usage1
	exit 1
	}


# function to test for minus at start of value of second part of option 1 or 2
checkMinus()
	{
	test=`echo "$1" | grep -c '^-.*$'`   # returns 1 if match; 0 otherwise
    [ $test -eq 1 ] && errMsg "$errorMsg"
	}

# test for correct number of arguments and get values
if [ $# -eq 0 ]
	then
	# help information
   echo ""
   usage2
   exit 0
elif [ $# -gt 18 ]
	then
	errMsg "--- TOO MANY ARGUMENTS WERE PROVIDED ---"
else
	while [ $# -gt 0 ]
		do
			# get parameter values
			case "$1" in
		     -help)    # help information
					   echo ""
					   usage2
					   exit 0
					   ;;
				-m)    # get  mode
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID MODE SPECIFICATION ---"
					   checkMinus "$1"
					   mode=`echo "$1" | tr '[A-Z]' '[a-z]'`
					   case "$mode" in 
					   		normal) ;;
					   		grayscale) ;;
					   		colorized) ;;
					   		shaded) ;;
					   		composite) ;;
					   		*) errMsg "--- MODE=$mode IS AN INVALID VALUE ---"  ;;
					   esac
					   ;;
				-e)    # get etch
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID ETCH SPECIFICATION ---"
					   checkMinus "$1"
					   etch=`expr "$1" : '\([0-9]*\)'`
					   [ "$etch" = "" ] && errMsg "--- ETCH=$etch MUST BE A NON-NEGATIVE INTEGER(s) ---"
					   testA=`echo "$etch <= 0" | bc`
					   [ $testA -eq 1 ] && errMsg "--- ETCH=$etch MUST BE A POSITIVE INTEGER ---"
					   ;;
				-B)    # get brightness
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID BRIGHTNESS SPECIFICATION ---"
					   #checkMinus "$1"
					   brightness=`expr "$1" : '\([-0-9]*\)'`
					   [ "$brightness" = "" ] && errMsg "--- BRIGHTNESS=$brightness MUST BE A NON-NEGATIVE INTEGER ---"
					   testA=`echo "$brightness < -100" | bc`
					   testB=`echo "$brightness > 100" | bc`
					   [ $testA -eq 1 -o $testB -eq 1 ] && errMsg "--- BRIGHTNESS=$brightness MUST BE AN INTEGER BETWEEN -100 AND 100 ---"
					   ;;
				-S)    # get saturation
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID SATURATION SPECIFICATION ---"
					   #checkMinus "$1"
					   saturation=`expr "$1" : '\([-0-9]*\)'`
					   [ "$saturation" = "" ] && errMsg "--- SATURATION=$saturation MUST BE A NON-NEGATIVE INTEGER ---"
					   testA=`echo "$saturation < -100" | bc`
					   testB=`echo "$saturation > 100" | bc`
					   [ $testA -eq 1 -o $testB -eq 1 ] && errMsg "--- SATURATION=$saturation MUST BE AN INTEGER BETWEEN -100 AND 100 ---"
					   ;;
				-H)    # get hue
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID HUE SPECIFICATION ---"
					   #checkMinus "$1"
					   hue=`expr "$1" : '\([-0-9]*\)'`
					   [ "$hue" = "" ] && errMsg "--- HUE=$saturation MUST BE A NON-NEGATIVE INTEGER ---"
					   testA=`echo "$hue < -360" | bc`
					   testB=`echo "$hue > 360" | bc`
					   [ $testA -eq 1 -o $testB -eq 1 ] && errMsg "--- HUE=$saturation MUST BE AN INTEGER BETWEEN -360 AND 360 ---"
					   ;;
				-c)    # get  color
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID COLOR SPECIFICATION ---"
					   checkMinus "$1"
					   color="$1"
					   ;;
				-C)    # get coloramt
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID COLORAMT SPECIFICATION ---"
					   checkMinus "$1"
					   coloramt=`expr "$1" : '\([0-9]*\)'`
					   [ "$coloramt" = "" ] && errMsg "--- COLORAMT=$coloramt MUST BE A NON-NEGATIVE INTEGER(s) ---"
					   testA=`echo "$coloramt < 0" | bc`
					   testB=`echo "$coloramt > 100" | bc`
					   [ $testA -eq 1 -o $testB -eq 1 ] && errMsg "--- COLORAMT=$coloramt MUST BE INTEGER(s) BETWEEN 0 AND 100 ---"
					   ;;
				-t)    # get  type
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID TYPE SPECIFICATION ---"
					   checkMinus "$1"
					   type=`echo "$1" | tr '[A-Z]' '[a-z]'`
					   case "$type" in 
					   		hardlight) ;;
					   		softlight) ;;
					   		overlay) ;;
					   		*) errMsg "--- TYPE=$type IS AN INVALID VALUE ---"  ;;
					   esac
					   ;;
				 -)    # STDIN and end of arguments
					   break
					   ;;
				-*)    # any other - argument
					   errMsg "--- UNKNOWN OPTION ---"
					   ;;
		     	 *)    # end of arguments
					   break
					   ;;
			esac
			shift   # next option
	done
	#
	# get infile and outfile
	infile="$1"
	outfile="$2"
fi

# test that infile provided
[ "$infile" = "" ] && errMsg "NO INPUT FILE SPECIFIED"

# test that outfile provided
[ "$outfile" = "" ] && errMsg "NO OUTPUT FILE SPECIFIED"


# setup temporary images
tmpA1="$dir/sketchetch_1_$$.mpc"
tmpB1="$dir/sketchetch_1_$$.cache"
trap "rm -f $tmpA1 $tmpB1; exit 0" 0
trap "rm -f $tmpA1 $tmpB1; exit 1" 1 2 3 15

# read the input image into the temporary cached image and test if valid
convert -quiet -regard-warnings "$infile" -alpha off +repage $tmpA1 ||
	echo "--- 1 FILE $infile DOES NOT EXIST OR IS NOT AN ORDINARY FILE, NOT READABLE OR HAS ZERO size  ---"

# set up etch
etching=""
for ((i=0; i<etch; i++)); do
	etching="$etching -sharpen 0x1"
done

# set up brighness, saturation, hue and contrast
bri=$((100+$brightness))
sat=$((100+$saturation))
hue=`convert xc: -format "%[fx:(200/360)*$hue+100]" info:`

# set up modulation
if [ "$brightness" = "0" -a "$saturation" = "0" -a "$hue" = "0" ]; then
	modulating=""
else
	modulating="-modulate $bri,$sat,$hue"
fi

if [ "$mode" = "normal" ]; then
	convert $tmpA1 \
		\( +clone $etching \) \
		-compose overlay -composite $modulating \
		"$outfile"
		
elif [ "$mode" = "grayscale" ]; then
	convert $tmpA1 \
		\( +clone $etching \) \
		-compose overlay -composite -modulate 100,0,100 \
		"$outfile"
		
elif [ "$mode" = "colorize" ]; then
	convert $tmpA1 \
		\( +clone $etching \) \
		-compose overlay -composite -modulate 100,0,100 \
		\( +clone -fill $color -colorize $coloramount \) \
		+swap -compose overlay -composite \
		"$outfile"
		
elif [ "$mode" = "shaded" ]; then
	convert $tmpA1 \
		\( +clone $etching \) \
		-compose overlay -composite -modulate 100,0,100 \
		-shade 135x45 \
		"$outfile"

elif [ "$mode" = "composite" ]; then
	convert $tmpA1 -write mpr:img \
		\( +clone $etching \) \
		-compose overlay -composite -modulate 100,0,100 \
		-shade 135x45 \
		mpr:img +swap -compose $type -composite \
		"$outfile"
fi

exit 0



